International Research Fellowship Program: Modeling Alpine Population Histories with Approximate Bayesian Computation

国际研究奖学金项目使美国科学家和工程师能够在国外进行9至24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项将支持Sean D. Schoville博士与Olivier Francois博士在法国格勒诺布尔理工学院开展为期24个月的研究。在过去的270万年里，冰川循环以重复的间隔导致了高山生态系统的快速、区域性重组。这些生态系统为研究最近的时空环境变化如何影响物种形成和群落聚集过程提供了一个自然复制的模型系统。目前，利用遗传数据推断种群的时空历史在很大程度上局限于一套有限的分析模型。近似贝叶斯计算（ABC）是一种方法方法，可用于扩展所考虑的人口模型集，并提供定量标准，以便在这些替代模型之间进行统计区分。本研究项目利用ABC方法，在三个地理上独立的高山生态系统中，跨越许多共生物种，研究高山种群的人口变化模式和分化时间。这一比较研究了北半球高山物种的空间、时间和人口变化是否遵循可预测的模式。本研究的训练目标包括群体遗传数据的统计分析、生物信息学和计算生物学。在应用方面，该研究通过在区分不同的进化假设时实施客观的统计标准，并允许建立在定量方法上的大范围比较，为生物地理学领域提供了重要的进展。气候变化和景观改造是高山物种进化史中共同存在的主要环境因子。证明这些环境因素在形成共分布物种进化中的重要性，将对持续的气候变化的影响和管理受威胁的高山物种所需的策略产生影响，无论是短期的生态生存能力还是长期的进化潜力。本研究发展了北半球高山生物多样性的国际合作项目，重点是进化史、生态系统组织和保护。

The International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award will support a twenty-four-month research fellowship by Dr. Sean D. Schoville to work with Dr. Olivier Francois at Grenoble Institute of Technology in France. Glacial cycles have caused rapid, regional reorganization of alpine ecosystems at repeated intervals in the last 2.7 million years. These ecosystems provide a naturally replicated model system to study how recent spatial and temporal environmental change can influence processes of species formation and community assembly. At present, the utilization of genetic data to make inferences about the spatial and temporal history of populations is largely restricted to a limited set of analytical models. Approximate Bayesian computation (ABC) is a methodological approach that can be used to expand the set of population models considered and provide quantitative criteria to statistically discriminate between these alternative models. This research project utilizes ABC methodology to examine patterns of demographic change and the timing of divergence in alpine populations, across many co-occurring species in three geographically independent alpine ecosystems. This comparison examines whether spatial, temporal and demographic change in alpine species follows predicable patterns across the Northern Hemisphere. Training objectives of this research include statistical analysis of population genetic data, bioinformatics, and computational biology. On the applied side, this research provides an important advance in the field of biogeography by implementing objective, statistical criteria when discriminating between alternative evolutionary hypotheses and allowing broad scale comparisons to be built on quantitative methods. Climate change and landscape modification are the primary environmental agents that are shared in the evolutionary history of alpine species. Demonstrating the importance of these environmental factors in shaping the evolution of co-distributed species will have implications for the effects of ongoing climate changes and the strategies needed to manage threatened alpine species both for short-term ecological viability and long-term evolutionary potential. This research develops international collaborative projects on alpine biodiversity across the Northern Hemisphere, focusing on evolutionary history, ecosystem organization and conservation.